<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <title>1_字符串形式的ref</title>
</head>

<body>
  <!-- 准备好一个“容器” -->
  <div id="test"></div>

  <!-- 引入react核心库 -->
  <script type="text/javascript" src="./js/react.development.js"></script>
  <!-- 引入react-dom，用于支持react操作DOM -->
  <script type="text/javascript" src="./js/react-dom.development.js"></script>
  <!-- 引入babel，用于将jsx转为js -->
  <script type="text/javascript" src="./js/babel.min.js"></script>

  <script type="text/babel">
    //创建组件
    class Demo extends React.Component {
      showFn = () => {
        const { input1 } = this
        alert(input1.value)
      }
      render() {
        return (
          <div>
            <button onClick={this.showFn}>btn</button>
            <input type="text" ref={current => this.input1 = current} />
          </div>
        )
      }
    }

    ReactDOM.render(<Demo />, document.getElementById('test'))
  </script>
</body>

</html>